Sex Chromosomes and Sex Determination in Lepidoptera

@article{Traut2007SexCA,
  title={Sex Chromosomes and Sex Determination in Lepidoptera},
  author={W. Traut and Ken Sahara and F. Marec},
  journal={Sexual Development},
  year={2007},
  volume={1},
  pages={332 - 346}
}
The speciose insect order Lepidoptera (moths and butterflies) and their closest relatives, Trichoptera (caddis flies), share a female-heterogametic sex chromosome system. Originally a Z/ZZ (female/male) system, it evolved by chromosome rearrangement to a WZ/ZZ (female/male) system in the most species-rich branch of Lepidoptera, a monophyletic group consisting of Ditrysia and Tischeriina, which together comprise more than 98% of all species. Further sporadic rearrangements created multi-sex… 

Figures and Tables from this paper

Sex chromosome evolution in moths and butterflies
TLDR
The Z chromosomes are highly conserved among Lepidoptera, much like the Z in birds or the X in mammals, but the W chromosome, which is present in most lepidopteran species, was incorporated in the sex chromosome system much later, about 90–100 MY ago.
The deep conservation of the Lepidoptera Z chromosome suggests a non-canonical origin of the W
TLDR
A comparative genomic analysis shows the deep conservation of the Z chromosome in Lepidoptera and supports a non-canonical origin of the W chromosome and confirms the extreme stability of well-differentiated sex chromosomes.
New Insights into the Evolution of the W Chromosome in Lepidoptera
TLDR
The conserved synteny of the Z chromosome across Tischeriidae and Ditrysia, along with the W chromosome absence in the lower ditrysian families Psychidae and Tineidae, suggests a possible independent origin of the W chromosomes in these 2 lineages.
Sex Chromosome Turnover in Moths of the Diverse Superfamily Gelechioidea
TLDR
Sex chromosome evolution in Gelechioidea supports an earlier hypothesis postulating that lepidopteran sex chromosome–autosome fusions can be driven by selection for association of Z-linked preference or host-independent isolation genes with larval performance and thus can contribute to ecological specialization and speciation of moths.
On the Neo-Sex Chromosomes of Lepidoptera
TLDR
The presence of neo-sex chromosomes in moth and butterflies (Lepidoptera), the largest group with female heterogamety, is described and the role of meiotic drive, genetic drift, and selection in the establishing of these derived sex chromosome systems are discussed.
A single female-specific piRNA is the primary determiner of sex in the silkworm
TLDR
It is shown that the silencing of Masc messenger RNA by Fem piRNA is required for the production of female-specific isoforms of Bmdsx in female embryos, and that Masc protein controls both dosage compensation and masculinization in male embryos.
Evolution of sex chromosomes in insects.
TLDR
The vast diversity of sex chromosome systems in insects--ranging from the classical male heterogametic XY system in Drosophila to ZW systems in Lepidoptera or mobile genes determining sex as found in house flies--implies that insects can serve as unique model systems to study various functional and evolutionary aspects of these different processes.
Sex Chromosomes of the Iconic Moth Abraxas grossulariata (Lepidoptera, Geometridae) and Its Congener A. sylvata
TLDR
The results suggest a relatively rapid molecular divergence of Abraxas W chromosomes by the independent spreading of female-specific repetitive sequences, and cross-species W-chromosome painting revealed considerable sequence differences between them.
Absence of W Chromosome in Psychidae Moths and Implications for the Theory of Sex Chromosome Evolution in Lepidoptera
TLDR
This study provides strong evidence for the absence of the W chromosome in Psychidae, thus supporting the hypothesis of two independent W chromosome origins in Tischeriidae and in advanced Ditrysia.
Rapid assessment of the sex of codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) eggs and larvae
TLDR
A multiplex PCR assay was developed, which co‐amplified the CpW2‐EcoRI sequence to identify the W chromosome and the Z‐linked Cpper sequence, which served as a positive control of accurate processing of tested samples.
...
...

References

SHOWING 1-10 OF 141 REFERENCES
Sex Chromosome Differentiation in Some Species of Lepidoptera (Insecta)
TLDR
The hypothesis that the lepidopteran W chromosome came into being at the base of the ‘advanced’ Lepidoptera is supported; it was presumably an autosome whose homologue fused to the original Z chromosome.
On the sex chromosome trivalent in some Lepidoptera females
TLDR
In four of the moth species investigated the metaphase plates of the first meiotic division of their oocytes show a trivalent in addition to the normal bivalents, which supports the view that the big chromosome to be found in several Lepidoptera species is the sex chromosome.
Sex Chromatin in Lepidoptera
TLDR
The lepidopteran sex chromatin appears to mirror the full evolutionary life cycle of a univalent sex chromosome from its birth through heterochromatinization to sporatic loss.
Unusual sex chromosome inheritance in six species of small ermine moths (Yponomeuta, Yponomeutidae, Lepidoptera)
TLDR
First meiotic division in females and males of Yponomeuta evonyrnellus, Y. rorellus and Y. cagnagellus was studied and the bivalents were observed to be nonhomologously associated at the telomeres during meiotic prophase.
Exploring the envelope. Systematic alteration in the sex-determination system of the nematode caenorhabditis elegans.
TLDR
Mutations in key regulatory genes have been used to create a series of stable populations in which sex is determined not by X chromosome dosage, but in a variety of other ways, many of which mimic the diverse sex-determination systems found in different animal species.
Sex chromatin and sex chromosome systems in nonditrysian Lepidoptera (Insecta)
TLDR
The data obtained support the hypothesis that the Z/ZZ sex chromosome system, the female heterogamety and the absence of the sex chromatin body in interphase nuclei are ancestral traits in the superorder Amphiesmenoptera.
Molecular divergence of the W chromosomes in pyralid moths (Lepidoptera)
TLDR
The hypothesis of the accelerated molecular divergence of the lepidopteran W chromosomes in the absence of meiotic recombination is supported.
SEX-LINKED GENES AND SPECIES DIFFERENCES IN LEPIDOPTERA
TLDR
In the six best-studied species complexes, more than half of all ecological, behavioral, or physiological differences among species are controlled by X-links, indicating strong bias toward X-linkage of genes for species differences.
Sex chromatin and chromosome numbers in Lepidoptera.
  • T. Ennis
  • Biology
    Canadian journal of genetics and cytology. Journal canadien de genetique et de cytologie
  • 1976
TLDR
Three classes of sex chromatin distribution have been encountered in a sample of Canadian Lepidoptera, and the exceptional occurrence of SC in females and males of a species suggests the need for caution in too universal an application of this interpretation.
Retrotransposable elements on the W chromosome of the silkworm, Bombyx mori
TLDR
It is found that many long terminal repeat (LTR) and non-LTR retrotransposons, retroposons, DNA transposons and their derivatives, have accumulated on the W chromosome as strata.
...
...